For items that are tracks of music on a compact disc, for example, some CD players enable a user to indicate his preference by programming a sequence in which the tracks are to be played. When one track ends, the CD player selects the next track based on the programmed sequence.
Some music playing devices and software allow a user to indicate a preference for a type of music, jazz for example, and the device or software will play items of music of the selected type.
In some systems, a selection is made of a next track to be played based on rating information provided by a user or a listening audience, such as a thumbs up/thumbs down rating. Other systems offer an automatic play list feature in which music items are selected for play based on user answers to questions that indicate preferences for types of music. At least one online merchant infers a user's tastes based on music purchased by the user.